Spring Framework

org.springframework.ejb.support
Class AbstractStatelessSessionBean

java.lang.Object
  extended by org.springframework.ejb.support.AbstractEnterpriseBean
      extended by org.springframework.ejb.support.AbstractSessionBean
          extended by org.springframework.ejb.support.AbstractStatelessSessionBean
All Implemented Interfaces:
java.io.Serializable, javax.ejb.EnterpriseBean, javax.ejb.SessionBean, SmartSessionBean

public abstract class AbstractStatelessSessionBean
extends AbstractSessionBean

Convenient base class for EJB 2.x stateless session beans (SLSBs), minimizing the work involved in implementing an SLSB and preventing common errors. Note that SLSBs are the most useful kind of EJB.

As the ejbActivate() and ejbPassivate() methods cannot be invoked on SLSBs, these methods are implemented to throw an exception and should not be overriden by subclasses. (Unfortunately the EJB specification forbids enforcing this by making EJB lifecycle methods final.)

There should be no need to override the setSessionContext() or ejbCreate() lifecycle methods.

Subclasses are left to implement the onEjbCreate() method to do whatever initialization they wish to do after their BeanFactory has already been loaded, and is available from the getBeanFactory() method.

This class provides the no-arg ejbCreate() method required by the EJB specification, but not the SessionBean interface, eliminating a common cause of EJB deployment failure.

Author:
Rod Johnson
See Also:
Serialized Form

Field Summary
protected  org.apache.commons.logging.Log logger
          Logger available to subclasses
 
Fields inherited from class org.springframework.ejb.support.AbstractEnterpriseBean
BEAN_FACTORY_PATH_ENVIRONMENT_KEY
 
Constructor Summary
AbstractStatelessSessionBean()
           
 
Method Summary
 void ejbActivate()
           
 void ejbCreate()
          This implementation loads the BeanFactory.
 void ejbPassivate()
           
protected abstract  void onEjbCreate()
          Subclasses must implement this method to do any initialization they would otherwise have done in an ejbCreate() method.
 
Methods inherited from class org.springframework.ejb.support.AbstractSessionBean
getSessionContext, setSessionContext
 
Methods inherited from class org.springframework.ejb.support.AbstractEnterpriseBean
ejbRemove, getBeanFactory, onEjbRemove, setBeanFactoryLocator, setBeanFactoryLocatorKey
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface javax.ejb.SessionBean
ejbRemove
 

Field Detail

logger

protected final org.apache.commons.logging.Log logger
Logger available to subclasses

Constructor Detail

AbstractStatelessSessionBean

public AbstractStatelessSessionBean()
Method Detail

ejbCreate

public void ejbCreate()
               throws javax.ejb.CreateException
This implementation loads the BeanFactory. A BeansException thrown by loadBeanFactory will simply get propagated, as it is a runtime exception.

Don't override it (although it can't be made final): code your own initialization in onEjbCreate(), which is called when the BeanFactory is available.

Unfortunately we can't load the BeanFactory in setSessionContext(), as resource manager access isn't permitted there - but the BeanFactory may require it.

Throws:
javax.ejb.CreateException

onEjbCreate

protected abstract void onEjbCreate()
                             throws javax.ejb.CreateException
Subclasses must implement this method to do any initialization they would otherwise have done in an ejbCreate() method. In contrast to ejbCreate, the BeanFactory will have been loaded here.

The same restrictions apply to the work of this method as to an ejbCreate() method.

Throws:
javax.ejb.CreateException

ejbActivate

public void ejbActivate()
                 throws javax.ejb.EJBException
Throws:
javax.ejb.EJBException
See Also:
This method always throws an exception, as it should not be invoked by the EJB container.

ejbPassivate

public void ejbPassivate()
                  throws javax.ejb.EJBException
Throws:
javax.ejb.EJBException
See Also:
This method always throws an exception, as it should not be invoked by the EJB container.

Spring Framework